1. Field of the Invention
The present invention relates to an IC device and, more particularly, to an IC device including a test easy circuit for facilitating a high-frequency test.
2. Description of the Related Art
In recent years, an operating frequency of an IC has been remarkably increased with a demand from an application field of, e.g., communication and computers, and the development of micro-lithography. In particular, an operating frequency of an IC such as a silicon ECL or a gallium arsenide IC reaches 500 MHz to several GHz.
On the other hand, in the manufacture of an IC, a test for IC chips arranged on a wafer is performed after the wafer manufacturing steps are completed. Although an LSI tester is conventionally used for this test, an LSI tester which is commonly employed at present can perform only a test using an operating frequency signal of a maximum of 200 MHz. For this reason, at present, it is difficult to perform a high-frequency test for the above-mentioned IC chip having an operating frequency of 500 MHz to several GHz using the conventional LSI tester.
Conventionally, when an operating frequency of an IC is increased to exceed a frequency used in a normal LSI tester for a test, high-speed measuring apparatuses are combined to test only a part of the IC. However, such measuring apparatuses are extremely expensive. In addition, when such a test system is prepared, equipment cost of a manufacturing line is increased, thus causing an increase in manufacturing cost.